查询词典 diffusive

Because the diffusive term is discretized with divided forward difference or divided backward difference according to the sign of convection velocity, these methods keep first order accuracy for diffusive term.

3.2考虑规则网格上的一维和二维定常型对流占优扩散问题，离散方法采用了有限体积方法及普通的有限差分方法，基本离散思想是将对流项提高到二阶精度，扩散项则根据对流速度的方向决定采用向前或向后差商离散。

Radiative transfer equation in cartesian coordinates can be considered as a special kind of convective- diffusive equation with strong convection characteristics.

直角坐标系下的辐射传递方程可以看作一类特殊的对流扩散方程，且具有强对流特性。

Numerical simulations of the three dimension viscous flow over the SUBOFF-1 model provided by DARPA and other two models are processed by solving RANS equations withκ-εtwo-equation turbulence model and finite volume method, and with SIMPLEC method for pressure-linked terms, central difference shemes for temporal derivative terms, and second-order upwind schemes for convective and diffusive terms.

本文基于RANS方程，采用κ-ε两方程湍流模型来封闭控制方程，采用有限体积法离散控制方程，对于速度压力关联方程，应用协调一致的SIMPLEC算法求解，变化率项用中心差分，对流扩散项采用二阶迎风格式，分别对DARPA提出的裸艇体SUBOFF-1模型以及另外两种回转体模型进行了数值模拟计算。

As for the diffusive term, it is shifted to undetermined time level to be discretized by divided central difference. The shifting error will be small for weak diffusion problems.

对于弱扩散问题，由于扩散系数比较小，这种转移引起的误差也比较小，从而可以期望得到更精确的数值结果。

Analytical solution of Smoluchowski equation, which diffusive term is constant and potential is Harmonic Oscillator form, is obtained.

给出了扩散项为常数，漂移项为谐振子位势形式的Smoluchowski方程的解析解。

In this paper, the analytical solution of Smoluchowski equation, of which diffusive term is constant and drift term harmonic oscillator potential (including the well and the barrier potentials), is derived from a simple Gaussian distribution in a easy and wizard method.

当扩散项为常数、漂移项为一维谐振子势(包括谐振子势阱和谐振子位垒)的情况下，得到Smoluchowski方程的解析表达式。

We find that maximal diffusive flux can be several times even scores of times larger than actual diffusive flux.

研究表明最大扩散气量可能是实际扩散气量的几倍甚至几十倍。

The influences of the shock thickness and Alfven waves on the particle acceleration by diffusive shock waves are numerically studied through solving one-dimensional diffusive equation including the second-order Fermi effect. It is shown that the spectral index of the energetic particles strongly depends on the shock thickness. For example, the spectral index increases from 2.1 to 3.7 in the low energy range of 3-10 MeV and from 2.5 to 5.0 in the high energy range of 20-60 MeV as the thickness increases. The spectral index decreases from 4.3 to 3.1 as the particle injection energy increases. The spectral index decreases from 4.0 to 1.8 at the quasi-steady stage with the enhancement of the compression ratio from 2 to 4. The results indicate that under the influence of Alfven waves, the energetic particle spectrum at lower energy becomes flat and the spectral index decreases from 2.5 to 0.6 in the low energy range of 3-10 MeV and from 11.6 to 5.0 in the high energy range of 20-60 MeV. At the same time, the rollover energy reaches 19.6 MeV. The spectral index decreases from 5.8 to 2.9 as the energy density of Alfven waves increase. All these results are basically consistent with the theoretical models, as well as the observations of typical energetic particle events.

通过数值求解包含二阶费米加速的一维扩散方程，探讨在准平行激波条件下激波厚度和级联阿尔芬波对粒子加速的影响，研究粒子分布函数的演化与激波厚度和阿尔芬波强度的内禀关系，计算结果表明：(1)考虑激波厚度时，谱指数明显依赖于激波厚度，随着厚度从0.32增大到2.56，低能端(3-10MeV)谱指数逐渐从2.1增加到3.7，高能端(20-60MeV)谱指数从2.4增大到5.0，能谱逐渐变软；当初始注入粒子动量增大1.3倍，质子能谱指数从4.3减小到3.1，且与零厚度激波加速的谱指数差值缩小；厚度不变时，随着压缩比从2增加到4，准稳态分布时低能端(3-10MeV)粒子能谱指数逐渐从4.0减小到1.8谱变硬；(2)在级联阿尔芬波的影响下，随着时间的增大，粒子在低能处(3-10MeV)的谱指数从2.5减小到0.6高能端(20-60MeV)谱指数从11.6减小到5.0，能谱变硬，拐点能量值从7.5MeV增大到为19.6MeV；随着波的能量密度增大，谱指数从5.8减小到2.9，这表明阿尔芬波强度越大，加速效率越高，通过与激波厚度解析结果和高能粒子事件的观测能谱比较发现两者是一致的，说明数值模拟结果是可靠的。

Of 11 cases of edema had diffusive uneven SCC lesions. 1 case of edema had single midline oval lesion of splenium. The brain lesions of edema were incontinuous. In follow-up MRI of 5 cases of brain edema, the lesions were disappeared. In 3 cases of cerebral infarct, the lesions of SCC and brain were lateral distribution. 2 cases of hemorrhagic disease had diffusive uneven lesions in SCC and ventricle.

水肿性病变(n=11)中10例MRI表现为SCC弥漫不均匀病灶、1例为居中类圆形病灶，颅内病灶呈跳跃不对称分布，5例MRI复查病灶消失。3例脑梗塞SCC及脑内病灶呈偏侧分布，脑内散在病灶以患侧较多。2例SCC出血，SCC病灶弥漫不均匀，并见脑室内出血。

Finally, the influence of the diffusive rate of signal molecules affected by noise on the dynamics of the multicellular system was also investigated, showing that the larger the diffusive rate, the better the synchronized switch and the larger the amplification factor.

最后，还分析了受噪声影响的信号分子的扩散率对细胞群体切换行为的影响。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失